U.S. patent application number 13/485527 was filed with the patent office on 2013-12-05 for isolation rings for packages and the method of forming the same.
This patent application is currently assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.. The applicant listed for this patent is Chih-Horng Chang, Min-Feng Ku, Tin-Hao Kuo, Tsung-Fu Tsai. Invention is credited to Chih-Horng Chang, Min-Feng Ku, Tin-Hao Kuo, Tsung-Fu Tsai.
Application Number | 20130320572 13/485527 |
Document ID | / |
Family ID | 49669258 |
Filed Date | 2013-12-05 |
United States Patent
Application |
20130320572 |
Kind Code |
A1 |
Chang; Chih-Horng ; et
al. |
December 5, 2013 |
Isolation Rings for Packages and the Method of Forming the Same
Abstract
A device includes a first package component, and a second
package component underlying, and bonded to, the first package
component. A molding material is disposed under the first package
component and molded to the first and the second package
components, wherein the molding material and the first package
component form an interface. An isolation region includes a first
edge, wherein the first edge of the isolation region contacts a
first edge of the first package component and a first edge of the
molding material. The isolation has a bottom lower than the
interface.
Inventors: |
Chang; Chih-Horng; (Taipei
City, TW) ; Kuo; Tin-Hao; (Hsin-Chu, TW) ;
Tsai; Tsung-Fu; (Changhua City, TW) ; Ku;
Min-Feng; (Hsin-Chu, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chang; Chih-Horng
Kuo; Tin-Hao
Tsai; Tsung-Fu
Ku; Min-Feng |
Taipei City
Hsin-Chu
Changhua City
Hsin-Chu |
|
TW
TW
TW
TW |
|
|
Assignee: |
TAIWAN SEMICONDUCTOR MANUFACTURING
COMPANY, LTD.
Hsin-Chu
TW
|
Family ID: |
49669258 |
Appl. No.: |
13/485527 |
Filed: |
May 31, 2012 |
Current U.S.
Class: |
257/787 ;
257/E21.502; 257/E23.116; 438/107 |
Current CPC
Class: |
H01L 21/82 20130101;
H01L 23/293 20130101; H01L 2924/1815 20130101; H01L 2924/181
20130101; H01L 21/56 20130101; H01L 23/3121 20130101; H01L 2924/181
20130101; H01L 24/97 20130101; H01L 23/49838 20130101; H01L 23/564
20130101; H01L 23/49827 20130101; H01L 2924/12042 20130101; H01L
25/0657 20130101; H01L 2924/12042 20130101; H01L 23/49822 20130101;
H01L 23/3135 20130101; H01L 21/565 20130101; H01L 2224/16225
20130101; H01L 21/78 20130101; H01L 2924/00 20130101; H01L 2924/00
20130101; H01L 21/304 20130101; H01L 21/561 20130101 |
Class at
Publication: |
257/787 ;
438/107; 257/E23.116; 257/E21.502 |
International
Class: |
H01L 23/28 20060101
H01L023/28; H01L 21/56 20060101 H01L021/56 |
Claims
1. A device comprising: a first package component: a second package
component underlying, and bonded to, the first package component; a
molding material under the first package component and molded to
the first and the second package components, wherein the molding
material and the first package component form an interface; and an
isolation region comprising a first edge, wherein the first edge of
the isolation region contacts a first edge of the first package
component and a first edge of the molding material, and wherein the
isolation region has a bottom lower than the interface.
2. The device of claim 1, wherein the first package component, the
second package component, and the molding material form a package,
and wherein a second edge of the isolation region and a second edge
of the molding material form an edge of the package.
3. The device of claim 1, wherein the isolation region forms a ring
encircling the first package component.
4. The device of claim 1, wherein the isolation region comprises
four inner edges contacting four edges of the first package
component.
5. The device of claim 1, wherein the first package component is a
laminate substrate, and wherein the molding material comprises a
molding compound.
6. The device of claim 1, wherein the isolation region comprises: a
wide portion extending from a top surface of the first package
component into the molding material, wherein the bottom of the
isolation region is a bottom of the wide portion; and a narrow
portion narrower than the wide portion, wherein the narrow portion
extends from the bottom of the wide portion further into the
molding material.
7. The device of claim 1, wherein the isolation region comprises a
solder resist.
8. A device comprising: a package substrate; a device die
underlying, and bonded to, the package substrate; a molding
compound under the package substrate and molded to the package
substrate and the device die; and a polymer encircling, and
contacting edges of, the package substrate, wherein the polymer
extends from a top surface of the package substrate to a level
lower than a top surface of the molding compound.
9. The device of claim 8, wherein the polymer and the molding
compound comprise different materials.
10. The device of claim 8, wherein the polymer has a density
greater than a density of the molding compound.
11. The device of claim 8, wherein the polymer is configured to be
dispensed in a form of liquid, and is configured to be cured to a
solid form from the liquid.
12. The device of claim 8, wherein the polymer comprises outer
edges opposite to inner edges of the polymer that contact the
package substrate, and wherein the outer edges of the polymer are
aligned to edges of the molding compound.
13. The device of claim 8, wherein the polymer comprises: a wide
portion extending from a top surface of the package substrate to
the level lower than the top surface of the molding compound; and a
narrow portion narrower than the wide portion extending from a
bottom of the wide portion into the molding compound.
14. The device of claim 8, wherein the polymer comprises a solder
resist.
15-20. (canceled)
21. A device comprising: a package substrate; a device die
underlying and bonded to the package substrate; a molding compound
under the package substrate, wherein the molding compound is in
contact with a bottom surface of the package substrate, and wherein
the device die is molded in the molding compound; and a polymer
ring encircling the package substrate and a top portion of the
molding compound, wherein the polymer ring comprises a bottom
surface contacting a first top surface of the molding compound.
22. The device of claim 21, wherein the polymer extends from a top
surface of the package substrate to a level lower than a second top
surface of the molding compound, and wherein the second top surface
is in contact with the bottom surface of the package substrate.
23. The device of claim 21, wherein the polymer ring comprises an
inner portion forming a first ring, and an outer portion forming a
second ring encircling the first ring, and wherein the first ring
comprises a first bottom surface, the second ring comprises a
second bottom surface, and wherein the first bottom surface of the
first ring is unleveled with the second bottom surface of the
second ring.
24. The device of claim 21, wherein the polymer and the molding
compound comprise different materials.
25. The device of claim 21, wherein the polymer comprises: inner
edges contacting the package substrate; and outer edges opposite to
the inner edges, wherein the outer edges of the polymer are aligned
to edges of the molding compound.
26. The device of claim 21, wherein the package substrate, the
device die, and the molding compound are comprised in a package,
and wherein outer edges of the polymer ring forms parts of edges of
the package.
Description
BACKGROUND
[0001] In the packaging of integrated circuits, device dies are
bonded onto package components such as package substrates in a
package substrate strip. The package substrates include metal
connections that are used to route electrical signals between
opposite sides of the respective package substrates. The dies may
be bonded onto one side of a package substrate strip using flip
chip bonding, and a reflow is performed to melt the solder balls
that interconnect the dies and the package substrates.
[0002] After the bonding of the device dies onto the package
substrate strip, a molding compound is molded onto the device dies
and the package substrate strip. The package substrate strip is
then sawed apart into a plurality of packages. Although the molding
materials are generally moisture proof, the moisture may still
penetrate into the resulting packages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] For a more complete understanding of the embodiments, and
the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
[0004] FIGS. 1 through 5B are top views and cross-sectional views
of intermediate stages in the formation of packages in accordance
with some exemplary embodiments; and
[0005] FIGS. 6 through 8 illustrate the formation of packages in
accordance with some alternative exemplary embodiments.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0006] The making and using of the embodiments of the disclosure
are discussed in detail below. It should be appreciated, however,
that the embodiments provide many applicable inventive concepts
that can be embodied in a wide variety of specific contexts. The
specific embodiments discussed are illustrative, and do not limit
the scope of the disclosure.
[0007] A package and a method of forming the same are provided in
accordance with various exemplary embodiments. The intermediate
stages of forming the package are illustrated. The variations of
the embodiments are discussed. Throughout various views and
illustrative embodiments, like reference numbers are used to
designate like elements.
[0008] FIG. 1 illustrates a top view of a package component 20. In
some embodiments, package component 20 is a package substrate
strip, and hence is referred to as package substrate strip 20
hereinafter, although package component 20 may also be another type
of package component such as an interposer wafer, a device wafer,
or the like. In the embodiments wherein package component 20 is a
package substrate strip, package substrate strip 20 includes a
plurality of package substrates 22, which are identical to each
other. In some embodiments, package substrates 22 are distributed
uniformly in one or both of the illustrated X and Y directions, and
may have the layout of an array.
[0009] Package substrates 22 may be laminate substrates, which
include a plurality of dielectric films 23 (shown in FIG. 2B)
adhered together through lamination, or may be build-up substrates.
Dielectric films may comprise composite materials that are mixed
with glass fiber and/or resin. Metal traces 28 and vias 30 (FIG.
2B) are formed in laminate dielectric films 23. As also shown in
FIG. 2B, electrical connectors 24 are formed on a surface of
package substrates 22, and are connected to electrical connectors
26 that are on the opposite side of the respective package
substrate 22 through metal traces 28. In some embodiments,
electrical connectors 24 are metal traces, which are used for
forming Bump-On-Trace (BOT) connections. In alternative
embodiments, electrical connectors 24 are metal pads, metal
pillars, composite connectors comprising metal pillars and solder
caps, or the like.
[0010] FIG. 2A illustrates a top view showing the bonding of
package components 32 onto package substrates 22 in FIG. 1. FIG. 2B
illustrates a cross-sectional view of FIG. 2A, wherein the
cross-sectional view is obtained from the plane crossing line 2B-2B
in FIG. 2A. In some embodiments, package components 32 are dies
(such as device dies comprising transistors), packages, or the
like. Referring to FIG. 2B, the bonding may be performed through
solder bonding, wherein electrical connectors 34 of package
components 32 are solder balls. In some exemplary embodiments, the
bonding is a BOT bonding.
[0011] As also shown in FIG. 2B, after the bonding of package
components 32 onto package substrates 22, polymer 35 is dispensed
to mold package components 32 and package substrates 22. In some
embodiments, polymer 35 is a molding compound, a molding underfill,
an epoxy, or the like. An underfill (not shown) may be dispensed
into the gaps between package components 32 and package substrates
22. Alternatively, no underfill is dispensed. Instead, polymer 35
is a molding underfill that is also disposed into the gaps besides
molding package components 32. Polymer 35 is then cured and
solidified.
[0012] Referring to FIGS. 3A and 3B, a grooving is performed on
package substrate strip 20 to form trenches 36. The grooving may be
performed using a blade, a laser beam, or the like. Referring to
FIG. 3A, trenches 36 are formed between package substrates 22, and
separate package substrates 22 from each other. Trenches 36 may
form a grid. FIG. 3B illustrates a cross-sectional view of the
structure shown in FIG. 3A, wherein the cross-sectional view is
obtained from the plane crossing line 3B-3B in FIG. 3A. As shown in
FIG. 3B, trenches 36 penetrate through package substrate strip 20,
extend into polymer 35, and stop at an intermediate level of
polymer 35. Accordingly, depth D1 of trenches 36 is at least
greater than thickness T1 of package substrate strip 20.
Furthermore, depth D2, which is the depth of the portions of
trenches 36 in polymer 35, may be greater than about 20 percent
thickness T2 of polymer 35, and may be between about 20 percent and
about 80 percent thickness T2. Width W1 of trenches 36 may be
between about 1,000 .mu.m and about 5,000 .mu.m.
[0013] An isolation material is filled into trenches 36, and is
cured (solidified) to form isolation regions 38. The resulting
structure is shown in FIGS. 4A and 4B. FIG. 4B illustrates a
cross-sectional view of the structure shown in FIG. 4A, wherein the
cross-sectional view in FIG. 4B is obtained from the plane crossing
line 4B-4B in FIG. 4A.The top surface of isolation regions 38 may
be slightly higher than, substantially level with, or lower than,
the top surfaces of package substrates 22. When filled into
trenches 36, isolation material 38 may be a liquid or a gel, which
has a viscosity low enough to fill into the micro-voids (not shown)
in polymer 35 (FIG. 5B). Isolation regions 38 may be a polymer, a
resin, or the like. In some exemplary embodiments, isolation
material 38 is a solder resist such as comprising Alkyd resin,
acrylated epoxy resin, methacrylated epoxy resin, or the like.
After the curing, isolation regions 38 may have a density greater
than the density of the cured polymer 35 in accordance with some
embodiments. For example, the ratio of the density of isolation
regions 38 to the density of polymer 35 may be greater than about 3
volume percent. The ratio of the density of isolation regions 38 to
the density of polymer 35 may be between about 97 volume percent
and about 100 volume percent in accordance with some embodiments.
The dispensing of the isolation material may be performed, for
example, through stencil printing.
[0014] Next, as also shown in FIG. 4B, a die saw is performed to
saw the structure in FIGS. 4A and 4B into a plurality of packages
40. Kerf lines 39 are between opposite edges 38A of isolation
regions 38. After the die sawing, there are remaining portions of
isolation regions 38 on opposite sides of kerf lines 39. FIGS. 5A
and 5B illustrate a top view and a cross-sectional view,
respectively, of package 40. As shown in FIG. 5A, isolation regions
38 are located at the peripheral region of package 40. It is
appreciated that although isolation regions 38 are referred to
using a plural form, isolation regions 38 may be parts of a same
continuous ring, as shown in FIG. 5A. The inner edges 38A of
isolation regions 38 are in contact with the edges of package
component 22.
[0015] Referring to FIG. 5B, outer edges 38B of isolation regions
38 also act as the edges of package 40. Outer edges 38B are aligned
to edges 35A of polymer 35. Inner edges 38A of isolation regions 38
are opposite to outer edges 38B, and are in contact with both
package substrate 22 and polymer 35. Furthermore, inner edges 38A
are in contact with interface 42 between polymer 35 and package
substrate 22.
[0016] In some embodiments, isolation regions 38 form a ring
encircling and contacting interface 42. Interface 42 is likely to
be the weak part in which moisture and detrimental chemical gases
may pass through. For example, the moisture may travel from open
air, through interface 42, and reach the internal features such as
electrical connectors 24. It is realized that the resistance to the
penetration of the moisture increases when the length of the
traveling path of the moisture increases. Accordingly, as shown in
FIG. 5B, assuming if isolation regions 38 are not formed, moisture
may travel from open air to electrical connectors 24 through paths
45. When isolation regions 38 are formed, moisture may travel from
open air to electrical connectors 24 through paths 46, which are
longer than paths 45. Since paths 46 are longer than paths 45, the
resulting package 40 has increased resistance to the penetration of
moisture and the detrimental chemical gases than in structures that
do not have isolation regions 38. As a result, since electrical
connectors suffer less from the moisture and detrimental chemicals,
the risk of short circuits between neighboring electrical
connectors 24 is reduced. For example, the short circuits may be
the result of the formation of dendrites between neighboring
electrical connectors 24, and the undesirable dendrites may further
be formed due to the oxidation of metal ions of electrical
connectors 24, the migration of the oxidized metal ions along
interface 42, and the reduction of the migrated metal ions.
[0017] FIGS. 6 and 7 illustrate the formation of package 40 in
accordance with alternative embodiments. In FIG. 6, trenches 36
include wide portions 36' and narrow portions 36'', which are
narrower than wide portions 36'. In the formation of trenches 36,
wide portions 36' are first formed, wherein wide portions 36' may
extend from the top surface of package substrate 22 into polymer
35. Wide portions 36' may form a grid since wide trenches 36' are
parts of trenches 36, which forms a grid, as shown in FIG. 3A.
Next, a plurality of narrow trenches 36'' is formed to extend from
the bottom of wide portions 36' deeper into polymer 35. Next, as
shown in FIG. 7, isolation material 38 is dispensed into trenches
36 to form isolation regions 38, which also include wide portions
and narrow portions. A die saw step is then performed to cut
package substrate strip 20, isolation regions 38, and polymer 35
into packages 40. The respective kerf lines 39 of the sawing are
illustrated.
[0018] FIG. 8 illustrates the formation of package 40 in accordance
with further embodiments. In these embodiments, isolation regions
38 include wide portions 38', narrow portions 38'', and additional
wide portions 38'''. In the formation of the trench of isolation
regions 38, the trenches for forming portions 38' and 38'' may be
formed before the sawing of package substrate strip 20, and the
trenches for forming portions 38''' may be formed after the sawing.
The filling of the isolation material 38 may be performed after the
die saw.
[0019] In accordance with embodiments, a device includes a first
package component, and a second package component underlying, and
bonded to, the first package component. A molding material is
disposed under the first package component and molded to the first
and the second package components, wherein the molding material and
the first package component form an interface. An isolation region
includes a first edge, wherein the first edge of the isolation
region contacts a first edge of the first package component and a
first edge of the molding material. The isolation has a bottom
lower than the interface.
[0020] In accordance with other embodiments, a device includes a
package substrate, and a device die underlying, and bonded to, the
package substrate. A molding compound is disposed under the package
substrate and molded to the package substrate and the device die. A
polymer encircles the package substrate and contacts edges of the
package substrate. The polymer extends from a top surface of the
package substrate to a level lower than a top surface of the
molding compound.
[0021] In accordance with yet other embodiments, a method includes
bonding a first package component to a second package component,
molding a molding material to the first and the second package
components, and forming a trench penetrating through the first
package component. The trench extends into the molding material. An
isolation material is filled into the trench to form an isolation
region. The isolation region and the molding material are sawed to
form a package, wherein the package includes a portion of the
isolation region.
[0022] Although the embodiments and their advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the embodiments as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, and composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed, that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the disclosure.
Accordingly, the appended claims are intended to include within
their scope such processes, machines, manufacture, compositions of
matter, means, methods, or steps. In addition, each claim
constitutes a separate embodiment, and the combination of various
claims and embodiments are within the scope of the disclosure.
* * * * *